Potassium cyanide test procedure (KCN test) microbiology

Potassium cyanide medium used to grow the certain kinds of bacteria. Some bacteria grow in the presence of KCN.

Potassium cyanide medium test Reagent (KCN test)

  • Nutrient Broth Base : 1 litter
  • Potassium Cyanide Solution 5% :     15 ml

Dispense the medium in 1 ml quantities into sterile tubes and stopper quickly with corks. Sterilize by heating in paraffin. The medium can be stored safely for two weeks at 4°C.

Potassium cyanide medium test procedure

Inoculate the tubes with a loopful of a 24-hours’ broth culture grown at 37°C.

Observe daily (for 2 days) for growth. A positive control of Proteus Vulgaris and a negative control of E.coli should be put up simultaneously.

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